SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8a18fd3c7480556e8633384fda0296ce27ed766d697da70906c43f658ed99cbd' 
  AND token = '3XFKvElbiWFDmIXpCWBXHzET3TfrG1JPWbDFHL3lml8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}